In recent years, a larger volume of sounds and a larger amount of data have come to be transmitted or received through radiocommunication. In a radiocommunication system, as far as point-to-point unicast communication is concerned, a different radio band is assigned to each wireless terminal and a connection is established by radio in order to perform communication. In contrast, in the case of multicast communication for distributing one content of sounds and data to multiple wireless terminals, a specific band within a radio band is assigned as a multicast resource. A wireless base station transmits a multicast content of sounds and data in the specific band. The content transmitted by way of the multicast resource is selectively received and decoded by a plurality of terminals. Thus, a multicast content distribution service addressed to the plurality of terminals is realized. When multicast communication is realized in this way, once data is transmitted in the specific band, the same data can be transmitted to the plurality of wireless terminals. Therefore, the radio band can be efficiently utilized.
As literatures concerning multicast communication, for example, Non-patent document 1 is available. In Non-patent document 1, for example, a packet format for multicast communication is stipulated. Non-patent document 2 stipulates a test application protocol for radiocommunication. Although Non-patent document 2 does not stipulate multicast communication, since Non-patent document 2 specifies a technology associated to the present invention, Non-patent document 2 is cited therein.
Non-patent document 1: 3GPP2 C.S0054-A (2.4.7.4.1.7.2)
Non-patent document 2: 3GPP2 C.S0029-A (Section 6)
Non-patent document 3: “Multiple OFDM Formats for EBM Packet Transmission,” C30-20050620-009